Before the 1950/60s all pencils were actual lead.
Edit: I was wrong. This comment is fake news.
That's not correct. Pencils were made out of graphite ever since it was first invented. It was mistakenly identified as black lead back then. The tradition of calling sticks of graphite “lead” has endured to this day. There was a form of writing instrument in ancient times before the pencil called a stylus that sometimes was made of lead.